Pneumatic equipment for synchronous piercing of slits

Abstract

A slitting equipment, piercing various patterns of ventilation slits in thin material, comprising a frame, a main cylinder, auxiliary cylinders, and a plate with knives. Upon an electric impulse from a bag-making machine, to which the present slitting equipment is attached, the auxiliary pneumatic cylinders press and stretch the thin material when the main pneumatic cylinder activates a plate, to which is attached a multitude of cutting knives, up and down the vertical plane. The sharp knives pierce and cut the stretched, thin film in the designed pattern. When the knives have disengaged from the material, the auxiliary cylinders release the film, and the latter is free to move horizontally, while restricted vertically by the top and bottom supports of the machine. As a result of this procedure, ventilation openings have been created simultaneously with the sealing and shaping processes carried on by the bag-making machine, without producing any waste material.

I claim: 
     
       1. A piercing apparatus comprising: a supporting bridge,   an upper frame,   a lower frame,   a platform affixed to said upper frame,   a central electronic processing unit, receiving electric signals from an external source, and emitting timed electric signals,   a pneumatic main cylinder mounted on the said platform,   a pneumatic main solenoid valve, when opened, allowing pressured air, conveyed by means of air-hoses, to activate said main cylinder,   auxiliary pneumatic cylinders mounted on said platform,   a pneumatic auxiliary solenoid valve, when opened, allowing pressured air, conveyed by means of air-hoses, to activate said auxiliary cylinders,   a pack of knives, comprising several knives distanced by means of spacers and fastened by means of rods to form an assembly, each knife having plural piercing elements, said assembly being attached to said pneumatic main cylinder to restrict the assembly to upward and downward motion, said downward motion having limiting means such that said plural piercing elements form plural, unconnected slits in a workpiece,   a guide-separator with prolonged orifices allowing for vertical movement of said pack of knives thru said guide-separator orifices, said guide-separator is connected to and vertically activated by said auxiliary cylinders,   a support separator with prolonged orifices allowing for vertical movement of said pack of knives in said support-separator orifices, said support-separator is fastened to said lower frame.   
     
     
       2. Piercing apparatus as claimed in claim 1 in which: said central electronic processing unit, upon an electric signal, opens said pneumatic auxiliary solenoid valve and allows compressed air, conveyed by means of air-hoses, to drive said auxiliary pneumatic cylinders down, thus propelling said guide-separator down toward said support-separator,   said central electronic processing unit, after propelling said guide-separator down, opens said main solenoid valve and allows compressed air, conveyed by means of air-hoses, to drive said main pneumatic cylinder rod down, thus propelling said knife pack, attached to a main cylinder rod, through said prolonged orifices of said guide-separator and said support-separator.   
     
     
       3. Piercing apparatus as claimed in claim 1 in which said pack of knives if further characterized by round openings at each extremity, enabling said knife pack to be connected to said main cylinder rod by a plate-holder and bolts.   
     
     
       4. Piercing apparatus as claimed in claim 1 in which said knife pack is parallel to said guide-separator and is restricted from twisting and rotating by means of guides, enveloped by a resilient matter, thereby limiting the downward motion of said knife pack, reducing impact and decreasing noise,   the main cylinder rod is enveloped by a resilient matter, thereby limiting the upward motion of said knife pack, reducing impact, and decreasing noise.